Global Patent Index - EP 2104355 A4

EP 2104355 A4 20121212 - IMAGE CODING APPARATUS AND IMAGE DECODING APPARATUS

Title (en)

IMAGE CODING APPARATUS AND IMAGE DECODING APPARATUS

Title (de)

BILDCODIERUNGSVORRICHTUNG UND BILDDECODIERUNGSVORRICHTUNG

Title (fr)

APPAREIL DE CODAGE ET DE DÉCODAGE D'IMAGE

Publication

EP 2104355 A4 20121212 (EN)

Application

EP 07860507 A 20071228

Priority

  • JP 2007075304 W 20071228
  • EP 07000368 A 20070109
  • EP 07860507 A 20071228

Abstract (en)

[origin: EP1944974A1] The present invention determines different additional a priori information for setting up an image filter depending on the spatial position of an image element within an image. The individual image elements of an image are assigned to one of a plurality of groups and an image filter is set up separately for each group of pixels based on additional a priori information. As the original image data is not available in a decoder, a conventional decoder can only use decoded image data for determining adaptive filter coefficients. However, this decoded image data includes disturbances, such as quantisation noise. The present invention generates additional data for improving the filter efficiency based on undisturbed image data. This additional data for setting up an image filter is determined depending on the spatial position of the pixels within an image. An image is separated into a plurality of groups and separate filter data is determined for each group. The decoder analyses the filter information and determines an adaptive set of filter coefficients for each group of image elements separately. Based on a determined filter coefficient, an adaptive filtering of the decoded image data is performed depending on the spatial positions of the individual image elements. In this way, the decoder applies an improved filtering.

IPC 8 full level

H04N 7/26 (2006.01); H04N 7/50 (2006.01)

CPC (source: EP US)

H04N 19/117 (2014.11 - EP US); H04N 19/136 (2014.11 - EP US); H04N 19/14 (2014.11 - EP US); H04N 19/157 (2014.11 - EP US); H04N 19/172 (2014.11 - EP US); H04N 19/176 (2014.11 - EP US); H04N 19/182 (2014.11 - EP US); H04N 19/46 (2014.11 - EP US); H04N 19/61 (2014.11 - EP US); H04N 19/80 (2014.11 - EP US); H04N 19/86 (2014.11 - EP US)

Citation (search report)

  • [XI] EP 0786904 A2 19970730 - LUCENT TECHNOLOGIES INC [US], et al
  • [XI] US 2005265452 A1 20051201 - MIAO ZHOURONG [US], et al
  • [XI] EP 1513349 A2 20050309 - MICROSOFT CORP [US]
  • [XI] US 6909745 B1 20050621 - PURI ATUL [US], et al
  • [A] US 5796875 A 19980818 - READ CHRISTOPHER JENSEN [US]
  • [A] WITTMANN S ET AL: "Post-filter hint SEI", 21. JVT MEETING; 78. MPEG MEETING; 20-10-2006 - 27-10-2006; HANGZHOU,CN; (JOINT VIDEO TEAM OF ISO/IEC JTC1/SC29/WG11 AND ITU-T SG.16 ),, no. JVT-U035, 25 October 2006 (2006-10-25), XP030006681, ISSN: 0000-0407
  • [A] WITTMANN S: "SEI on post-filter hints for high-fidelity", 20. JVT MEETING; 77. MPEG MEETING; 15-07-2006 - 21-07-2006;KLAGENFURT, AT; (JOINT VIDEO TEAM OF ISO/IEC JTC1/SC29/WG11 AND ITU-TSG.16 ),, no. JVT-T039, 15 July 2006 (2006-07-15), XP030006526, ISSN: 0000-0408
  • [A] ATZORI L ET AL: "Low-complexity post-processing for artifact reduction in block-DCT based video coding", IMAGE PROCESSING, 2000. PROCEEDINGS. 2000 INTERNATIONAL CONFERENCE ON SEPTEMBER 10-13, 2000, PISCATAWAY, NJ, USA,IEEE, 10 September 2000 (2000-09-10), pages 668 - 671, XP010530073, ISBN: 0-7803-6297-7
  • [A] HAO-SONG KONG ET AL: "Edge map guided adaptive post-filter for blocking and ringing artifacts removal", PROCEEDINGS / 2004 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS : MAY 23 - 26, 2004, SHERATON VANCOUVER WALL CENTRE HOTEL, VANCOUVER, BRITISH COLUMBIA, CANADA, IEEE OPERATIONS CENTER, PISCATAWAY, NJ, 23 May 2004 (2004-05-23), pages III - 929, XP010719412, ISBN: 978-0-7803-8251-0
  • See also references of WO 2008084745A1

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR

DOCDB simple family (publication)

EP 1944974 A1 20080716; EP 2104355 A1 20090923; EP 2104355 A4 20121212; JP WO2008084745 A1 20100430; US 2010021071 A1 20100128; WO 2008084745 A1 20080717

DOCDB simple family (application)

EP 07000368 A 20070109; EP 07860507 A 20071228; JP 2007075304 W 20071228; JP 2008553083 A 20071228; US 52240607 A 20071228